The MSH-4 is a transformerless, phantom-powered, tube-driven omnidirectional small-diaphragm microphone. Inside is a subminiature tube (Raytheon JAN 6418) which imparts a pleasant character to the sound. To maximize dynamic range and the sonic enhancement of the tube, place the MSH-4 close to the source, even within 12 inches (30cm). Unlike cardioid microphones, the omnidirectional MSH-4 does not have increased bass response due to proximity effect. The MSH-4 retains a natural response regardless of source distance.
The maximum level of the microphone is rated at 112dBSPL; at that level, higher-order distortion begins to increase. The MSH-4 will not be harmed by higher levels, however, the signal may be clipped.
With the subminiature tube in a small case, the MSH-4 is vulnerable to handling noise (źmicrophonics╗). When using your MSH-4, it is highly recommended that a padded clip or a shockmount be used. Switch on phantom power after the mic is mounted, and allow at least 3 minutes for the tube to warm up and the microphone to settle. To reposition the MSH-4, switch off phantom power, reposition, turn phantom power back on, then allow another 2 or 3 minutes to for the microphonic noise to completely subside.
The MSH-4 requires a +48V phantom power supply that is capable of supplying 10mA per microphone, according to DIN standard 45 596/IEC standard 268-15A. The MSH-4 will function poorly or not at all when connected to a nonconforming power supply.